Question

AB is tangent to circle O find the length of radius r to the nearest tenth please answer ASAP will mark as brainlist

Answer 1

Answer:

7.62

Step-by-step explanation:

Using Phythagoras' theorem...

Hyp^2 = a^2 + b^2

that is:

8^2 = 11^2 + r^2

64 = 121 + r^2

64-121 = r^2

58 = r^2

therefore r = sqrt of 58

NB: Not sure but there you go.

Answer 2

Answer:

r ≈ 3.6

Step-by-step explanation:

∠ OAB is right ( angle between tangent and radius at point of contact )

then Δ OAB is a right triangleΔ

using Pythagoras' identity in the right triangle

with hypotenuse OB = r + 8 , then

OB² = OA² + AB² , that is

(r + 8)² = r² + 11²

r² + 16r + 64 = r² + 121 ( subtract r² from both sides )

16r + 64 = 121 ( subtract 64 from both sides )

16r = 57 ( divide both sides by 16 )

r = $\frac{57}{16}$ ≈ 3.6 ( to the nearest tenth )